1. Field of the Invention
The present invention relates to a saturation adjustment method and related color adjustment system, and more particularly, to a saturation adjustment method and related color adjustment system for compensating over-saturation adjustment.
2. Description of the Prior Art
In general, manufacturers of displays provide display products with functionality of OSD (On-Screen Display) adjustment for allowing users to adjust hue, saturation and brightness of image color. That is, users are allowed to adjust the image color of displays in a preset range by making use of the OSD adjustment. For instance, the user may adjust the original hue of red color to approach purple color, adjust the original low saturation to become higher saturation, or adjust the original high brightness to become lower brightness.
FIG. 1 is a schematic diagram showing a well-known color wheel 100. As shown in FIG. 1, the color wheel 100 is normally sectioned into a plurality of hue regions R1-R12. The peripheral radius of the color wheel 100 is utilized to represent a preset full-scale saturation Sfull. The hue of a color coordinate P is represented by a corresponding hue angle θ, and the saturation of the color coordinate P is presented by a corresponding radius Sp. Traditionally, the method for adjusting the saturation of a color coordinate corresponding to an interested hue comprises adjusting the full-scale saturation corresponding to the hue edge of a hue region including the interested hue, adjusting the full-scale saturation corresponding to the interested hue based on the adjusted full-scale saturation corresponding to the hue edge, and adjusting the saturation of the color coordinate based on the adjusted full-scale saturation corresponding to the interested hue.
FIG. 2 is a schematic diagram showing a color wheel having over-saturation adjustment. As shown in FIG. 2, the preset full-scale saturation Sfull corresponding to the hue edge 230 of the hue region R3 of the color wheel 200 is adjusted to become the full-scale saturation Sfullx greater than the preset full-scale saturation Sfull, which implies an over-saturation adjustment situation. Accordingly, the full-scale saturations corresponding to the hue region R3 between the hue edge 230 and the hue edge 235 are adjusted based on the full-scale saturation Sfullx and the preset full-scale saturation Sfull. In the processes of the prior-art saturation adjustment method, the saturation of a color coordinate greater than the preset full-scale saturation Sfull is adjusted to become the preset full-scale saturation Sfull. However, based on the prior-art saturation adjustment method, the saturations over the preset full-scale saturation Sfull are all set to become the preset full-scale saturation Sfull and cannot be distinguished between each other. That is, the saturation levels between the preset full-scale saturation Sfull and the full-scale saturation Sfullx are sacrificed and are not available for distinction after the prior-art saturation adjustment. Furthermore, the saturation adjusting processes at opposite sides of the hue edge 230 between the hue regions R3 and R4 are based on different processing modes, and an abrupt change of saturation adjusting processes may significantly redistribute the original color profile and distort the original image feature. In summary, the prior-art saturation adjustment method is likely to cause image color distortion and degrade the display quality.